The stress process in occupational settings

This thesis is concerned with the direct and indirect mechanisms through which psychosocial stressors affect well-being, within the framework of the Michigan Model (House, 1981). An additional aim is to examine the stress process during workplace transitions. Empirical studies were conducted in three occupational settings: a cross-sectional pilot study with a sample of white-collar employees of several companies (N=144), and two longitudinal studies with samples drawn from a single retail chain, the "manager study" (N=261) and the "relocation study" (N=175). Although statistical control for individual differences (including response style) attenuated associations between work characteristics and strain outcomes, in all three samples work characteristics jointly contributed to the explanation of job satisfaction and psychological distress. More specifically, perceptions of control and social support were associated with job satisfaction, while work demands played a significant role in explaining symptom report. Furthermore, symptom levels predicted work absence in a combined sample of retail employees (N=221). In addition to direct effects, mediation and moderation patterns were examined. Results suggested that work perceptions partially mediated relations between personality (specifically locus of control beliefs and neuroticism) and strain. A similar pattern of mediation was apparent for social support. However, evidence for moderation of the stress process by individual and work characteristics was equivocal. Cross-sectional analyses using the manager sample data revealed significant interactions of control and Type A behaviour with work characteristics, but these interactions were not consistent in form with theory and past research. In contrast, in the longitudinal relocation study interactions were consistent with expectations: the negative impact of change was buffered by social support from senior colleagues and perceptions of control. Longitudinal analyses also demonstrated negative effects of workplace change; decreasing job satisfaction was observed during organisational restructuring, and transfer to a new branch was associated with increased psychological distress. Furthermore latent variable models revealed that changes in support, role ambiguity, and control over time were predictive of changes in job satisfaction. Overall, the present studies emphasise the need to examine simultaneously the joint influences of individual and work characteristics in occupational stress research. In this way the direct and indirect mechanisms through which psychosocial factors influence strain may be more fully understood, and strain-reducing interventions devised.</p

The stress process in occupational settings: the role of psychosocial factors

This thesis is concerned with the direct and indirect mechanisms through which psychosocial stressors affect well-being, within the framework of the Michigan Model (House, 1981). An additional aim is to examine the stress process during workplace transitions. Empirical studies were conducted in three occupational settings: a cross-sectional pilot study with a sample of white-collar employees of several companies (N=144), and two longitudinal studies with samples drawn from a single retail chain, the "manager study" (N=261) and the "relocation study" (N=175). Although statistical control for individual differences (including response style) attenuated associations between work characteristics and strain outcomes, in all three samples work characteristics jointly contributed to the explanation of job satisfaction and psychological distress. More specifically, perceptions of control and social support were associated with job satisfaction, while work demands played a significant role in explaining symptom report. Furthermore, symptom levels predicted work absence in a combined sample of retail employees (N=221). In addition to direct effects, mediation and moderation patterns were examined. Results suggested that work perceptions partially mediated relations between personality (specifically locus of control beliefs and neuroticism) and strain. A similar pattern of mediation was apparent for social support. However, evidence for moderation of the stress process by individual and work characteristics was equivocal. Cross-sectional analyses using the manager sample data revealed significant interactions of control and Type A behaviour with work characteristics, but these interactions were not consistent in form with theory and past research. In contrast, in the longitudinal relocation study interactions were consistent with expectations: the negative impact of change was buffered by social support from senior colleagues and perceptions of control. Longitudinal analyses also demonstrated negative effects of workplace change; decreasing job satisfaction was observed during organisational restructuring, and transfer to a new branch was associated with increased psychological distress. Furthermore latent variable models revealed that changes in support, role ambiguity, and control over time were predictive of changes in job satisfaction. Overall, the present studies emphasise the need to examine simultaneously the joint influences of individual and work characteristics in occupational stress research. In this way the direct and indirect mechanisms through which psychosocial factors influence strain may be more fully understood, and strain-reducing interventions devised

The stress process in occupational settings

This thesis is concerned with the direct and indirect mechanisms through which psychosocial stressors affect well-being, within the framework of the Michigan Model (House, 1981). An additional aim is to examine the stress process during workplace transitions. Empirical studies were conducted in three occupational settings: a cross-sectional pilot study with a sample of white-collar employees of several companies (N=144), and two longitudinal studies with samples drawn from a single retail chain, the "manager study" (N=261) and the "relocation study" (N=175). Although statistical control for individual differences (including response style) attenuated associations between work characteristics and strain outcomes, in all three samples work characteristics jointly contributed to the explanation of job satisfaction and psychological distress. More specifically, perceptions of control and social support were associated with job satisfaction, while work demands played a significant role in explaining symptom report. Furthermore, symptom levels predicted work absence in a combined sample of retail employees (N=221). In addition to direct effects, mediation and moderation patterns were examined. Results suggested that work perceptions partially mediated relations between personality (specifically locus of control beliefs and neuroticism) and strain. A similar pattern of mediation was apparent for social support. However, evidence for moderation of the stress process by individual and work characteristics was equivocal. Cross-sectional analyses using the manager sample data revealed significant interactions of control and Type A behaviour with work characteristics, but these interactions were not consistent in form with theory and past research. In contrast, in the longitudinal relocation study interactions were consistent with expectations: the negative impact of change was buffered by social support from senior colleagues and perceptions of control. Longitudinal analyses also demonstrated negative effects of workplace change; decreasing job satisfaction was observed during organisational restructuring, and transfer to a new branch was associated with increased psychological distress. Furthermore latent variable models revealed that changes in support, role ambiguity, and control over time were predictive of changes in job satisfaction. Overall, the present studies emphasise the need to examine simultaneously the joint influences of individual and work characteristics in occupational stress research. In this way the direct and indirect mechanisms through which psychosocial factors influence strain may be more fully understood, and strain-reducing interventions devised.</p

Mammographic surveillance in women younger than 50 years who have a family history of breast cancer: tumour characteristics and projected effect on mortality in the prospective, single-arm, FH01 study.

BACKGROUND: Evidence supports a reduction in mortality from breast cancer with mammographic screening in the general population of women aged 40-49 years, but the effect of family history is not clear. We aimed to establish whether screening affects the disease stage and projected mortality of women younger than 50 years who have a clinically significant family history of breast cancer. METHODS: In the single-arm FH01 study, women at intermediate familial risk who were younger than 50 years were enrolled from 76 centres in the UK, and received yearly mammography. Women with BRCA mutations were not explicitly excluded, but would be rare in this group. To compare the FH01 cohort with women not receiving screening, two external comparison groups were used: the control group of the UK Age Trial (106,971 women aged 40-42 years at recruitment, from the general population [ie, average risk], followed up for 10 years), and a Dutch study of women with a family history of breast cancer (cancer cases aged 25-77 years, diagnosed 1980-2004). Study endpoints were size, node status, and histological grade of invasive tumours, and estimated mortality calculated from the Nottingham prognostic index (NPI) score, and adjusted for differences in underlying risk between the FH01 cohort and the control group of the UK Age Trial. This study is registered with the National Research Register, number N0484114809. FINDINGS: 6710 women were enrolled between Jan 16, 2003, and Feb 28, 2007, and received yearly mammography for a mean of 4 years (SD 2) up until Nov 30, 2009; surveillance and reporting of cancers is still underway. 136 women were diagnosed with breast cancer: 105 (77%) at screening, 28 (21%) symptomatically in the interval between screening events, and three (2%) symptomatically after failing to attend their latest mammogram. Invasive tumours in the FH01 study were significantly smaller (p=0·0094), less likely to be node positive (p=0·0083), and of more favourable grade (p=0·0072) than were those in the control group of the UK Age Trial, and were significantly less likely to be node positive than were tumours in the Dutch study (p=0·012). Mean NPI score was significantly lower in the FH01 cohort than in the control group of the UK Age Trial (p=0·00079) or the Dutch study (p<0·0001). After adjustment for underlying risk, predicted 10-year mortality was significantly lower in the FH01 cohort (1·10%) than in the control group of the UK Age Trial (1·38%), with relative risk of 0·80 (95% CI 0·66-0·96; p=0·022). INTERPRETATION: Yearly mammography in women with a medium familial risk of breast cancer is likely to be effective in prevention of deaths from breast cancer